Why doesn't Internet Explorer display the correct XML transformation when I return to the page using the Back button?

I am generating some XML data in a Delphi application in response to an HTTP GET request, using TIdHTTPServer

to detect it and send the response. XML links to the XSLT stylesheet to render the HTML page. This works fine, the page displays OK.

Then I click the link on the page to go to another data layer, everything is OK again. The problem is, if I then go back, the previous page is re-rendered, but some data (not all) is different, but my server has not received another GET HTTP request to generate the XML. If I go to refresh in IE then my server will receive the HTTP GET and restore the page correctly.

If I use other browsers it works fine all the time. I tried adding META tags to stop caching pages in XSLT, but that doesn't make any difference. IE does not request the page again.

I would prefer not to host specific XML data as sensitive client data.